Growing with Cob

Growing, a company at the beginning of its journey, plans to build healthy homes, schools and housing estates using cob and other natural materials. Harriet Sandilands writes about their recent flagship project, a cob studio, which has enabled them to master their expertise and serves as a functional example of the sort of work they hope to carry out in the future.

London does not seem like the most obvious place to find a mud hut. Yet, Growing ‘ a small, natural building company in the Capital, have found that the ancient art of cob has a most definite role to play within the urban environment. Not least because the process uses up waste materials to form concrete-hard structures that will last for centuries.

Commonplace in the regions of Devon and Cornwall as early as the 13th Century, Cob is a clayey subsoil aggregate ‘ sand and water, mixed together to create a pliable building material that can be hand-sculpted into just about anything. Known cob structures to date include such things as ovens, houses, garden walls and skyscrapers, not to mention interior design features, from bookshelves and benches to arches, vaults and alcoves.

Growing’s studio/meeting place, in a back garden in North London, was built using clay from local skips or building sites and sand recycled from roadwork stones. It was finished with a timber roof of antique pine, reclaimed from various demolition sites around London.

The cob was mixed by foot on top of tarpaulins. With no power tools and only natural materials to deal with, this was the most benign and peaceful building site in the whole city, even getting the odd heron or swan swooping over from a neighbouring reservoir. They weren’t the only visitors.

Growing hosted several summer ‘open weekends’, during which people from the area revelled in getting muddy and playing their part in building something beautiful. Probably the most democratic building technique there is: cob disregards race, training, age and ability. Anyone can mix and apply it.

Growing’s new studio adheres to the *Oregon Cob style. Luxuriant curves avoid trees and create separate inside spaces. The passive solar design, the straw bales on the north wall and a rocket stove, an uber-efficient wood burner made from cob with a recycled oil drum that heats a cob bench, make the place a cosy retreat from high-octane London life.

Just as traditional cob houses rose up resembling the earth they came and were made from, this studio fits unobtrusively into its environs. The malleable material has allowed the team to avoid trees and fit the building snugly into an unused corner of the family garden. The reddish clay also gives a London feel to the earthen studio.

The idea of urban cob seems incongruous, yet it is the perfect fit: a building technique that can, in very real terms, bring communities together, use up local waste, channel misused energy and relieve stress. With all the issues over climate change, cob’s excellent thermal properties and its non-polluting construction processes have earned it a place at the fore-front of modern building.

*Oregon Cob differs from original cob: instead of just soil, clay and sand are mixed together. Wet bricks are used instead of ‘lifts’ or courses. The walls can be thinner but still retain their structural stability, allowing for more curvatures and arches.